Overview
ISO 14175:2008 - Welding consumables - Gases and gas mixtures for fusion welding and allied processes - specifies a harmonized system to classify and designate shielding, backing, process and assist gases used in fusion welding and related processes. The standard covers common processes (per ISO 4063) such as tungsten inert gas (TIG) welding, gas‑shielded metal arc welding (GMAW), plasma welding/cutting, laser welding/cutting and arc braze welding. Its purpose is to help users select the correct shielding gas by chemical properties and metallurgical behaviour and to simplify qualification procedures.
Key topics and technical requirements
- Scope: Applies to gases and mixtures used in fusion welding and allied processes; fuel gases and resonator gases for lasers are excluded. Gases may be supplied liquid or gaseous but are used as gases.
- Classification system: Main groups and subgroups (I, M1–M3, C, R, N, O, Z) based on reactivity and component ranges. Argon/helium are base gases; oxygen, CO2, hydrogen and nitrogen are common components.
- Designation format: Classification + chemical symbols + nominal compositions (e.g., ISO 14175 – M25 – ArCO – 6/4; ISO 14175 – I3 – ArHe – 30).
- Component tolerances: Mixture tolerances are specified (Table 3): for component >5% nominal, ±10% of nominal; for 1–5% nominal, ±0.5% absolute; <1% not specified.
- Purity and moisture: Minimum purities and maximum moisture/dew point values are defined by main group (Table 4). Moisture may be stated as ppm or dew point at 0.101 MPa.
- Testing & retesting: Composition and impurity testing requirements; failed tests must be retested per clause 9.
- Marking: Containers must be marked with manufacturer/supplier name, trade name, ISO 14175 designation and required health/safety warnings.
- Other notes: Argon may be partly or fully substituted by helium for classification. Transportation and handling follow local/regional regulations.
Applications and users
ISO 14175 is practical for:
- Welding engineers selecting shielding gases for TIG, MIG/MAG, plasma or laser welding
- Procurement and quality teams specifying gas supplies and acceptance criteria
- Gas manufacturers, distributors and testing laboratories for product labeling, mixing tolerances and purity control
- Welding procedure qualification and certification bodies where standardized gas classification simplifies approvals
Benefits include improved weld quality control, consistent procurement specifications, and clearer communication between suppliers and end users.
Related standards
- ISO 4063 - Nomenclature of welding processes (process numbers referenced)
- ISO 31‑0 - Quantities and units (rounding rules)
- Bibliography references: ASTM E260, JIS Z 3253 (shielding gases) - useful for testing and national practice
Keywords: ISO 14175:2008, welding consumables, shielding gases, gas mixtures, fusion welding, gas classification, purity, dew point, mixture tolerances.